Balance and hairspring timepiece regulator



March 14, 1950 F/MARTI BALANCE AND HAIRSPRING TIME1?IECE REGULATOR Filed Aug. 22, 1945 fiy.

Patented Mar. 14, 1950 BALANCE AND HAIRSPBI NG TIMEPIECE' REGULATOR" FritaMartL-La Chaux de Ponds, Switzerland Application au' astz z, 1945; seria1No; 6312,02; in Switzerland septeihberlz, 1944 1 Claim.

The" present invention relatesto a balance and hairspring. time-piece" regulator of the k'in'd' in which the operative'lehgth'ofthehairspriiig is automatically increased when the amplitude of the balance exceeds a predetermined value in order that the tendency to a diminution of the period due to the increase of the amplitude be annulled by the effect of the increase of the oper ative-length of the hairspring.

The invention consists, principally, in a single curb member arranged on one side of the outer coil of the hairspring and in means adapted to press said hairspring and said curb member against each other so that the hairspring does not leave the curb member but when the amplitude of the balance exceeds a predetermined value.

The accompanying drawing represents a common balance and hairspring time-piece regulator and two embodiments of the invention.

Fig. 1 is a diagrammatic plan view of the common regulator.

Figs. 2 and 3 are diagrammatic plan views illustrating each one of the above embodiments.

In Fig. 1, the reference character I indicates the balance staii and 2 indicates the hairspring whose inner end is fixed by a ferrule to the staff I, while the outer end is fixed in the usual way to the stud 3 which is itself fixed to the frame. 4 is the regulator lever which may be turnable about the balance staff and between the curb pins 5 and 6 of which passes the outer coil of the hairspring. The operative length of the hairspring is comprised between the pins 5 and 6 and the inner end of the hairspring. 001 indicates the position of rest of the balance which oscillates from its extreme right hand position 0A1 to its extreme left hand position 0A2. The angle OloA1=O1-OA2 is the amplitude and T may designate the period or time required by the balance to travel from 0A1 to 0A2.

As already known, this period T depends also upon the operative length of the hairspring and increases when this length increases, a fact which permits of general retouching of the oscillating system by turning the regulator lever in clockwise or counter-clockwise direction. It is further known that when the balance oscillates alone, its oscillations are isochronous, the period T being thus independent from the amplitude, while when the balance is combined with an escapement the face of things changes. The effect of the escapement is generally to diminish the period in the case of large amplitudes thus causing the watch to advance, while in the case of small amplitudes it increases the perio'd;=- th'u s" causing the watch to retard. On the" other hand upon winding up'of the watch maximumamplitudes of the-balance are obtained for in thatmoment the" escapement acts with maximum force on the balance. As a result of all that, a watch with 24 hours barrel advances in the morning and retards at night, so that finally at the end of the day the Watch will indicate the correct time. However in case of watches with eight or thirty days barrel, the advance will continue several days through thus causing inadmissible differences.

It is an object of the present invention to remove these inconveniences.

In the embodiment of Fig. 2, the regulator lever 4 carries only one curb pin I mounted on an eccentric disc 3 turnable in the regulator lever. The curb pin 1 is placed adjacent the outer coil of the hairspring on the inner side thereof. Suppose now that the disc 8 is turned in the direction of the arrow I so as to press the curb pin 1 against the hairspring. As long as the balance will oscillate in the direction of the arrow i the hairspring bears against the curb pin 1 and its operative length is comprised between curb pin and its inner end. Suppose now the balance moves from its position of rest 001 in the direction of the arrow i if the curb pin was not pressed against the hairspring, the latter should immediately leave this pin and its operative length should be measured from the stud 3 and thus increased by 1. However the pressure exerted by the curb pin 1 on the hairspring may be chosen so that this hairspring does not leave the pin but after a predetermined amplitude in the direction of the arrow f As long as this predetermined amplitude will not be exceeded, the operative length will remain constant; let us designate this length with L; from the moment in which this amplitude will be exceeded, the operative length will automatically become L+Z. This increase of the operative length will cause an increase of the period which will act all the longer as the amplitude is greater. However the increase of amplitude causes also a diminution of the period by the action of the escapement. It will be seen that the length I may be chosen so that these two effects will compensate each other.

The Fig. 3 represents a further embodiment in which the single curb pin I is fixed to the arm of the regulator lever B. It is here the hairspring which is pressed against this pin 5 by thestud 13 to which is fastened the outer end or the hairspring. The stud I3 is mounted rotatably in the cock l so that it may turn about its axis, thus according to its angular position, the hairspring will be pressed more or less firmly against the curb pin 1. The stud I3 is provided with an arm ll whose extremity is passed through by a screw l5 whose point bears against the cock. By screwing or unscrewing the screw I5 the angular position of the stud l3 and thus the pressure of the hairspring against the curb pin 1 may be ad- Justed. The balance wheel is designated by I I.

What I claim is:

A watch regulator comprising a cock, a hairspring for a balance wheel journalled therein, a regulator lever pivoted on said cock, concentrically to said balance wheel and formed with a rigid arm extending radially therefrom, a single fixed curb member secured to said arm, a stud rotatably mounted in said cock for fixing the outer end of the concentrical outer coil of said hairspring, said stud being formed with an arm, a screw passing through the extremity of said arm and bearing against the cock, said screw being adapted to adjust the angular position or said stud thus regulating the pressure with which said concentrical outer coil of the hairspring bears radially against said single curb pin, whereby said outercoil is not allowed to leave said single curb pin but when the amplitude of the balance wheel exceeds a predetermined value.

FRITZ MAR'II.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 318,780 Mirklebach May 26, 1885 2,307,841 Marti Jan. 12, 1943 2,340,677 Marti Feb. 1, 1944 FOREIGN PATENTS Number Country Date 21,474 Switzerland Apr. 17, 1900 83,152 Switzerland Apr. 16, 1920 

